1. Field of the Invention
This invention relates to cationic extended terminated polyamide resins, their preparation, and their use for increasing the wet strength of paper. Relevant United States classes appear to be 162/164, 260/29.2 and 260/78.
2. Description of the Prior Art
The closest known prior art are U.S. Pat. Nos. 2,926,116; 2,926,154; 3,125,552; 3,535,288; and 3,645,954; and French Pat. No. 884,271 (which corresponds to Belgian Pat. No. 446,643).
U.S. Pat. No. 2,926,116 discloses a paper wet strength resin that is uncured, thermosetting, and cationic, and which comprises a water-soluble polymeric reaction product of epichlorohydrin and a polyamide derived from a polyalkylene polyamine and a saturated aliphatic dibasic carboxylic acid containing from 3 to 10 carbon atoms.
U.S. Pat. No. 2,926,154 is a continuation-in-part of U.S. Pat. No. 2,926,116 and differs essentially in that the polyalkylene polyamines contain two primary amine groups and at least one secondary amine group, and the preferred saturated aliphatic dibasic carboxylic acids are those having from 3 to 8 carbon atoms, plus diglycolic acid.
U.S. Pat. No. 3,125,552, discloses a paper wet strength resin which comprises a water-soluble polymeric reaction product of epichlorohydrin and a polyamide derived from a polyalkylene polyamine having at least two primary amine groups and at least one secondary amine group, and an unsaturated polycarboxylic acid having at least one carbon to carbon double bond.
U.S. Pat. No. 3,535,288 discloses a paper wet strength resin which comprises a polyamide, which is the reaction product of an amino carboxylate and a polyalkylene polyamine, and which is then reacted with epichlorohydrin.
U.S. Pat. No. 3,645,954 discloses a paper wet strength resin which is made by reacting an aliphatic dicarboxylic acid with a polyalkylene amine, reacting the resulting polyamide with a lactam, and then reacting the resulting block copolyamide with epichlorohydrin.
French Pat. No. 884,271 discloses a resin for improving paper, inter alia, which comprises the reaction product of epichlorohydrin with an amine, which is then further reacted with a compound containing a reactive hydrogen atom, such as certain carboxylic acids, alcohols, or amines; as well as the epoxidation of a polyamide produced from a polyamine and an acid ester.